Scarred and scattered Missouri prairies hold secret to carbon storage
Less than one-half of one percent of Missouri’s native prairies remain today. The nutrient rich soil beneath its tall grasses made this land ideal for farming, so most of the state’s prairies were plowed in the 19th and 20th centuries.
The carbon-storing roots and microbial life that prairies foster could be one of the greatest assets in the fight against greenhouse gas emissions, but Missouri’s unprecedented wet period threatens to encroach upon the health of remaining prairies.
“We don’t know exactly in Missouri if the climate will become long-term dryer or wetter, but wetter weather would certainly favor more woody species,” Carol Davit, Executive Director of the Missouri Prairie Foundation said.
Although forests and woodlands fill an important ecological role, including carbon storage, they are no substitute for native prairie. The trees in some forests may sequester more carbon than equivalent areas of grassland, but when wildfires take hold, burning trees release their stored carbon. Grasslands retain it in their root structures, according to research from the University of California, Davis.
“Their roots can store tremendous amounts of carbon: in many cases much more effectively than in woody landscapes,” Davit said.
Carbon dioxide is the primary greenhouse gas emitted by human activities, and accounts for 80% of all greenhouse gas emissions. Carbon dioxide emissions increased by 3% from 1990 to 2019 in the United States, according to data from the EPA.
One reason prairies are able to store so much carbon, in addition to enriching soil so effectively, is because two-thirds of a prairie’s biological structure is underground. By comparison, only about one-third of a forest’s biomass is underground, Missouri Conservation Department Natural Community Ecologist and MPF Technical Advisor Mike Leahy said in a webinar last May.
“The things we’ve done to alter the landscape chip away at its ability to sequester carbon,” John George, MDC Regional Wildlife Supervisor, said. “The landscape was more productive as a native, natural landscape than it is as an altered landscape that we live in today.” There is no substitute for the biodiversity of remaining native prairie ecosystems. While a healthy grassland can house over 300 species of plants, animals, and invertebrates, converted pastures typically have less than 50 species present, he explained.
“They’re probably dominated by a dozen species; you’d have to work hard to find the other 30 or 40 that might be there,” George said.
Penn-Sylvania Prairie, for example, is a world-record winning example of the biodiversity that can exist within a healthy prairie. Botanist Brett Budach recorded 46 native plant species in a 20×20 inch square sample of the prairie in 2018.
Among these species are countless wildflowers pollinators depend on: prairie blazing star, purple coneflower, prairie indigo, and rattlesnake master, to name just a few. Some pollinators, such as the Regal Fritillary Butterfly, cannot survive without specific plants found only in native prairies. The Regal Fritillary caterpillars can only survive by feeding on prairie violets, and so due to the decline in prairies, they’re a species of conservation concern, George said. And they’re far from the only species reliant on the ecosystems that remaining prairies provide.
Another threat to the biodiversity of Missouri’s managed prairies, which receive care from the conservation department or conservationist organizations, is invasive species: plants that spread aggressively, dominating the landscape and reducing biodiversity. Those species deemed to be most severe by the Missouri Invasive Plant Task Force range from Callery pear to garlic mustard, Chinese bushclover, bush honeysuckles, and Himalayan blackberry.
To control these invasive plants, the department usually attempts to eliminate specific plants, using as little herbicide as possible to neutralize their spread.
“You have to use the smallest brush you can to achieve the desired effect,” George said. The department also uses prescribed burns, mowing, and even controlled grazing to eliminate unwanted vegetation before it produces seeds.
Another overarching threat, Davit said, particularly for land not in conservation ownership, is agricultural conversion.
In recent years, farmers across the country converted millions of acres of grasslands, wetlands, and woodlands into row crops as prices rose, according to the Midwest Center for Investigative Reporting.
One alternative for farmers who need an income from their unplowed land is conservation easement programs, which pay landowners to keep their wildland wild. Davit said the Prairie Foundation advocates for expansion of such programs and stronger conservation measures during each Farm Bill cycle. Farmers can also receive money for conservation measures through the Soil and Water Conservation program.
George encourages interested landowners to contact their local Private Lands Conservationists (PLC) about properly managing their prairie or woodland areas. PLCs are willing to consult with landowners who want assistance with treating invasive species or setting up controlled burns. Above all, he wants to encourage landowners to consider the excitement and fun that would result from witnessing certain species thriving in properly managed prairies or diverse prairie plantings.
“It requires patience. Usually, the first few years of trying to get things established, it doesn’t look the way you expected it to look,” he said. “Some of these species take four, five, six, seven years after you’ve planted them to show up in your planting, so it can be really fun and exciting when you finally see them having some success on your property.”